An asynchronous key agreement method and device for secure instant messaging

Abstract

This invention relates to the instant messaging field, particularly to an asynchronous key negotiation method and device aiming at secure instant messaging. Aiming at the problems existed in the prior art, this invention provides an asynchronous key negotiation method and device aiming at secure instant messaging; an instant messaging client performs key negotiation and exchange with the help of an instant messaging server directly; each interaction gets through the instant messaging server, and whether the instant messaging client is online or not is not sensitive; and thus, the asynchronous key negotiation is achieved. Simultaneously, since the method adopts a key rolling mechanism, a conversion temporary key and a protection key thereof are generated dynamically and updated in rolling; and thus, different messages use different conversion keys and protection keys thereof, so that the group messages can be protected and separated with each other by different keys among different uses in a same group.

Description

technical field [0001] The invention relates to the field of instant communication, in particular to an asynchronous key agreement method and device for secure instant communication. Background technique [0002] As a flexible modern communication method, instant messaging software brings great convenience to people, but also has great security risks. In order to solve the security problems of instant messaging, a variety of safe instant messaging software. In order to jointly establish a session key, secure instant messaging software needs to conduct key negotiation between two or more clients before communicating. Since instant messaging not only has the function of group communication, but also has the ability to send and receive offline messages, which makes The key negotiation of instant encrypted communication is different from other encrypted communication methods. The key negotiation of existing secure instant communication products can be divided into certificate t...

AI Technical Summary

Problems solved by technology

[0004] One is that the session key is not temporarily generated every time, but is calculated by the dot multiplication algorithm. This kind of session key is actually a fixed key, that is, for a certain client, the session key used by all messages at any time is the same , the hidden danger of this method is that once the session key of a certain message is cracked at a certain time, there is no confidentiality for all the previous and subsequent messages of the client; the other is that although the session key is temporarily generated each time, However, the protection key of the session key is actually a fixed key, that is, for a certain client, the session protection key used by all messages at any time is the same. The protection key of the session key of the message is deciphered, and all previous and subsequent messages for this client have no confidentiality at all

[0005] To sum up, the current key agreement protocols for real-time encrypted communication on the market, once the attacker masters these insecure devices, there is a risk of leaking or cracking the session key or the protection key of the session key. Or after cracking, the forward and backward security of the above-mentioned secure instant communication cannot be guaranteed

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